Can an exposed molar implant be covered up by the crown?

The simple answer is yes. Exposure of of a few of the threads of the implant does not affect the stability or function of the implant itself. A crown can be made to cover the the threads close to the gum line. A good lab technician can do this by having the metal substructure extend over the exposed implant, then cover that with porcelain.

It is possible to cover the implant with a crown. This will require a new abutment and crown. Also, the implant must be prepared along with the abutment in the mouth to design a crown that will cover both.

Whether a crown does or does not cover the entire implant depends on many variables that are out of the control of the dentist. And there is nothing diagnostically wrong if the crown does not cover the the treads or lower portions of the implants. Therefore asking for refund is not reasonable . Unless you are having discomfort or other diagnostic issues, I would simply accept that replacement of s tooth is NEVER going to be as good as Tooth that mother nature placed in the mouth. Doctors can do so much. If you do have discomfort or other issues, then seek a prosthodontist ( specialist) for advice.

If you had an angioplasty done for your heart and the surgery didn't work you wouldn't get a refund, you would get another surgery (and at full fee). This is no different.If you mean that your implant THREADS are showing, then no, the crown won't hide/cover it. You MAY be able to graft over it, but "it depends."I suggest to either allow your dentist to do what they deem best, or seek help/advice from a local specialist. It may be a simple solution.